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2 Sheets-Sheet 1 (No Model.)

W. D; FORBES.

SCREW THREADING MACHINE.

Pa tented Jan. 9, 1883.

W JJVVEJIVT'ORI M M fi m KM l M WITNESSES:

N. PETEfls PhnXo-Lilhognlphcr. Wiuhinglon, D. c.

I (No Model.) I W. D. FORBES. SCREW THREADING MAGHINE.

N0. 270,407. Patented Jan. 9,1883.

2 Sheets-Sheet 2.

FIG .9?

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WILLIAM DKFORBES, F BRIDGEPORT, CONNECTICUT, ASSIGNOR- OF ONE- HALFTORODERICK P. CURTIS, OF SAME PLACE. I

SCREW-TH READING MACHINE.

SPECIFICATION forming part of Letters Patent No. 270,407, dated January9, 188 3.

Application filed July17, 1882. (X0 model.) Patented in England May 26,1882, No. 2,508.

.1" 0 all whom it may concern:

Be it known that I, WILLIAM D. FORBES, a citizen of the United Statesand a resident of Bridgeport, Connecticut, have invented certainImprovements in Screw-Threading Machines, of which the following is aspecification.

My invention relates to certain improvements in the die-stocig for whichLetters Patent of the United States No. 253,996 were granted to me onthe 21st day of February,

1882, my present improvements relating to certain details ofconstruction too fully described hereinafter to need preliminaryexplanation.

In the accompanying drawings, Figure 1,

Sheet 1, is a longitudinal section of my improved die-stock; Fig. 2, anend view looking in the direction of the arrow 1, Fig. 1; Fig. 3, Sheet2, an end view looking in the direction of the arrow 2, Fig. l 5 Fig. 4,a view of part of the tool drawn to a larger scale than the otherfigures.

A is the fixed casing of the stock, B the diecarrying ring, and D theholder for the pipe to be threaded. In a projection, E, on the cas- 2ing A are formed bearings for the journals of a worm, a, which gearsinto teeth formed on the periphery of the die-carrying ring B. This ringhas a flange, b, in which are formed rccesses (1 (three in thepresentinstance) for the 0 reception of the rounded outer ends, 0, ofthe dies F, the inner ends of which are threaded in the usual manner,and project through openings in a flange,f, formed upon the cover-plateG, which is secured to the face of the die-carrying ring by screws 6,the stems of the latter passing through slots 0. Fig. 2, in thecoverplate. When the ring B is turned in the direction of the arrow,Fig. 2-, the rear edges of the pivoted dies will bear upon blocksgon thering, and the dies will cut a thread upon a tube or rod subjected totheir action, but when the ring is stationary, and the cover-plate G ismoved in the direction of the arrow, the dies will be caused to swingupon their pivots, ow-

ing to the action upon the dies of the flangef of the cover-plate, andthe pipe or rod will be freed from the dies, so as to be withdrawnlongitudinally. By turning the cover-plate G in a direction the reverseof that shown by the 0 arrow the dies will be turned down, so as to beagain brought into operative position.

Instead of actuating the dies by means ot' the flangef, the cover-platemay have internally-projecting pins adapted to act upon said dies.

On the rear of the die-carrying ring is a threaded flange, h, the pitchof the thread being similar to that of the dies F, and to this threadedflange is adapted a nut, m, which is swiveled by means of a flangedring, a, to the pipe-holderD. Underordinarycircumstances the nut m islocked tothe ring a by means of a spring-bolt, 1), adapted to openingsin said ring and nut, and to a slot, (1, in the casing A, so that as thedie-carrying ring is rotated, the pipe-holder is caused tolongitudinally traverse the casing, and thus properly present the pipeto the dies F. On withdrawing the bolt 1), however, by means of athumb-nut, 8, adapted to the threaded stem of the bolt, the nut m can befreed from the pipe-holder, and the ring B can then be rotated withoutimparting any longitudinal movement to the said holder, the nutmturning'with the threaded flange It. This operation is resorted to whenit is desired to cut the end of the pipe, a cutter, I, being adapted toa recess, k, in the die-carrying ring B, and being acted upon 'by afeed-screw, i, the head of which is confined between lugs on the ring B,and has openings for the reception of a suitable implement introducedthrough a slot in the cover-plate G, and serving to turn the feed-screw,so as to project or retract the cutter.

Thepipe to be threaded is clamped between a pair of V-shaped jaws, K,adapted to suitable guides on the holder D, and controlled byfeed-screws t, which are adapted to threaded openings in the jaws, andjournaled at the outer ends in lugs V on the holder. These 0 feed-screwshave ratchets to, which are acted upon by pawls carried by a forkedlever, M, journaled on the stems of the screws, as shown. The pawls arereversible, so that by vibrating the lever M the feed-screws may be sooperated as to advance or retract the jaws and grip or release the pipe.

Theobjectot' constructing the dies and hanging them to the diecarryingring in the mannershown is to chcapen the manufacture of the tool, thedies being simple steel bars having the rounded endsc formed thereon bysuitaroo Me tools, and the segmental openings (1 being" simply milled inthe flange b of the ring B.

I. claim as my invention- 1. The combination of the casing A, thediecarrying ring adapted to be rotated in the easing, a lead-screw, 71on the said ring, and the pipe-holder I) guided in the casingindependently of the lead-screw, and having a not adapted to the saidlead-screw, ali'substantiaily as set forth.

2. The combination of the casing A, the rotating die-carrying ringhaving a lead-screw, h,the pipe-holder having a nut, m, and devices forsecuring" said nut to and releasing it from the pipeholder, as setforth.

3. The combination of the ring B and the pivoted dies h with the fixedabutment-blocks g and the cover-plate Gr, having a fiange,f, or

projections adapted to act upon the dies F, as set forth. a i

4. The combination of the pipe-holder D, the sliding jaws K, thefeed-screws t, with ratchets w, and the forked lever M, carrying pawisadapted to said ratchets, as set forth.

5. The combination of the rotating die-carrier 13 having a lead-screw,the pipe-holder I), having a flanged ring, n, the nut m,confinedthereby, the spring-bolt p, and the thumb-nut s thereon, as set forth.

In testimony whereof I have signed my name tothis specification in thepresence of two subscribing witnesses.

\VI LLIAM I). FORBES.

Witnesses .HARRY DRUR-Y, HARRY SMITH.

